Cygnus subclass

The Cygnus subclass was a class of Federationstarship in operation during the 23rd century, the third batch of Hermes class starships built. Unlike its Hermes and Monoceros class predecessors, the Cygnus was specially outfitted to serve as a diplomatic and command courier

According to the Star Fleet Technical Manual, the Cygnus was designed to serve in a diplomatic/command courier role.

The class may have been named for the constellation Cygnus, as all the ships of that class appear to be named for constellations representing birds (with the exception of Columbia, which may be a misspelling of the constellation Columba--the dove).